Bragg Creek
Clear Sky Chart
History

This sumarizes the distribution of each different forecast outcome for the Bragg Creek clear sky chart from 2005-11-05 to

2017-09-12
.

This page is a summary of past forecasts. Even though it's based only on forecasts, some people use these pages as clue to a site's climate. But climate data based on actual observation should be preferred (if you can find it!).

Cloud, Transparency and Seeing forecasts are summarized individually. But because good observing conditions require a combination of minimum cloud cover, transparency and seeing, the individual forecast summaries can be difficult to interpret. The observing conditions section counts the combinations of conditions needed for common types of astronomical observation.

Observing Conditions

The following tables count the occurrence of the combinations of forecast and darkness conditions needed for different observations. Conditions are rated by by what percentage of the hours the observation would likely be attempted are usable.
Observation TypeMinimum conditions for hour to be usableOut of hours
Clear of CloudsTransparencySeeingSky Brightness
Planetary:50%(no limit)Average(no limit)Nighttime Hours
Deep Sky:70%Average(no limit)5.9Nighttime Hours
CCD Imaging:70%Below AveragePoor(no limit)Nighttime Hours

Percentages are of nighttime hours per month, or per year, when a particular observing conditions was met. Deep Sky percentages never exceed 50% because the moon is up half the time. Deep sky percentages are much lower for charts at high latitudes because of fewer dark hours in the summer.

Overall

PlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
Night
37%
15129
14%
46740
8%
15096
43%
15096
22%
30577

By Month

MonthDays of MonthPlanetaryData
Pts
Deep Sky
Max 60%
Data
Pts
Both Planetary and Deep Sky
Max 60%
Data
Pts
Either Planetary or Deep SkyData
Pts
CCD ImagingData
Pts
January1st to 15thNight
24%
900
13%
2685
5%
895
32%
895
17%
1874
January16th to endNight
25%
800
19%
2720
10%
800
37%
800
19%
1731
February1st to 15thNight
30%
701
15%
2429
9%
697
40%
697
19%
1553
February16th to endNight
34%
632
16%
1962
10%
632
43%
632
21%
1315
March1st to 15thNight
27%
720
15%
2129
6%
720
38%
720
21%
1433
March16th to endNight
31%
768
13%
2073
3%
768
38%
768
18%
1502
April1st to 15thNight
32%
640
11%
1720
4%
640
36%
640
18%
1250
April16th to endNight
35%
540
12%
1620
9%
540
39%
540
19%
1138
May1st to 15thNight
43%
406
10%
1421
10%
406
47%
406
20%
913
May16th to endNight
40%
374
5%
1309
4%
374
41%
374
15%
930
June1st to 15thNight
42%
360
1%
1260
0%
360
42%
360
16%
888
June16th to endNight
53%
360
1%
1260
0%
360
53%
360
25%
772
July1st to 15thNight
60%
340
3%
1190
0%
340
60%
340
27%
699
July16th to endNight
64%
376
10%
1299
11%
354
67%
354
32%
708
August1st to 15thNight
67%
387
14%
1459
19%
385
70%
385
28%
813
August16th to endNight
61%
573
21%
1719
17%
573
64%
573
41%
917
September1st to 15thNight
55%
667
18%
1780
12%
667
57%
667
38%
1075
September16th to endNight
49%
656
21%
1815
12%
656
56%
656
36%
1089
October1st to 15thNight
38%
660
17%
1945
9%
660
46%
660
21%
1322
October16th to endNight
37%
704
20%
2288
10%
704
50%
704
25%
1437
November1st to 15thNight
25%
805
18%
2380
8%
805
36%
805
24%
1507
November16th to endNight
24%
900
13%
2697
4%
900
32%
900
20%
1813
December1st to 15thNight
29%
900
14%
2700
7%
900
35%
900
17%
1918
December16th to endNight
27%
960
17%
2880
6%
960
36%
960
19%
1980

Individual Forecasts

The length of each colored bar in the "occurrence of each Forecast" column is proportional to the number of times the chart forecast that color. The percentages are of the total number of hours per month, or per year, with a particular forecast. The colors as the same as those used in clear sky charts.

Note: Transparency probabilities are only counted for those hours that have 30% or less cloud cover. Seeing probabilities are only counted for those hours that have 80% or less cloud cover. If that's too tricky, try Observing Conditions instead.

Overall

Occurrence of each ForecastData
Points
Cloud CoverDay
9%8%36%6%35%5%6%8%35%
47953
Night
6%8%36%5%35%5%6%8%40%
46892
Cloud CoverDay
9%8%36%6%35%5%6%8%35%
47954
Night
6%8%36%5%35%5%6%8%39%
46895
TransparencyDay
44%9%16%19%8%1
47609
Night
39%9%16%22%10%1
46740
SeeingDay
16%12%30%26%11%3
5979
Night
10%10%33%29%13%2
15134

By Month

Percentage Cloud Cover NW (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
26%29%5%36%5%7%9%41%
1253
16th to endDay
17%410%7%46%35%9%38%
1515
February1st to 15thDay
17%47%8%46%6%6%8%37%
1435
16th to endDay
19%6%11%6%47%5%6%7%32%
1512
March1st to 15thDay
16%5%7%8%46%6%6%8%37%
1830
16th to endDay
5%13%6%11%6%46%5%6%8%24%
2149
April1st to 15thDay
10%15%5%6%6%35%46%7%25%
2227
16th to endDay
13%14%36%5%45%5%5%7%29%
2340
May1st to 15thDay
11%10%47%6%46%5%5%7%31%
2528
16th to endDay
24%8%36%6%45%5%5%7%21%
2802
June1st to 15thDay
22%8%37%6%36%5%6%6%22%
2700
16th to endDay
15%5%36%6%37%5%6%9%31%
2700
July1st to 15thDay
10%5%15%5%35%6%7%8%38%
2700
16th to endDay
7%424436%6%7%9%44%
2779
August1st to 15thDay
13%425%5%35%5%7%8%37%
2491
16th to endDay
9%323435%46%8%47%
2483
September1st to 15thDay
13%5%14433435%50%
2098
16th to endDay
9%5%14435%449%46%
1815
October1st to 15thDay
11%10%35%5%345%6%8%34%
1681
16th to endDay
5%8%47%5%35%5%6%8%39%
1584
November1st to 15thDay
49%45%437%5%6%7%40%
1467
16th to endDay
29%5%7%6%2347%7%42%
1260
December1st to 15thDay
27%5%8%8%47%48%9%31%
1260
16th to endDay
28%38%6%35%5%7%9%38%
1344
January1st to 15thNight
28%5%8%7%36%6%7%8%35%
2685
16th to endNight
27%48%6%35%5%6%9%40%
2720
February1st to 15thNight
37%36%6%46%5%6%10%39%
2418
16th to endNight
29%49%7%35%5%47%39%
1962
March1st to 15thNight
17%46%7%46%6%8%10%36%
2129
16th to endNight
49%5%9%7%26%6%6%9%33%
2070
April1st to 15thNight
8%14%6%7%5%245%6%7%31%
1720
16th to endNight
8%14%37%42346%8%35%
1620
May1st to 15thNight
8%11%35%4245%5%9%38%
1420
16th to endNight
20%10%35%42345%8%30%
1309
June1st to 15thNight
18%8%36%435%5%47%33%
1260
16th to endNight
12%4134345%7%11%40%
1260
July1st to 15thNight
6%414446%5%6%8%47%
1260
16th to endNight
6%414225%5%5%7%54%
1388
August1st to 15thNight
11%41432346%8%49%
1467
16th to endNight
9%31221336%8%56%
1719
September1st to 15thNight
12%6%13322246%53%
1780
16th to endNight
10%41332346%8%50%
1815
October1st to 15thNight
11%8%36%5%3446%7%39%
1945
16th to endNight
6%8%35%4335%6%8%44%
2288
November1st to 15thNight
38%345%35%5%6%7%45%
2380
16th to endNight
38%48%7%445%5%8%38%
2697
December1st to 15thNight
28%47%7%46%6%7%9%33%
2700
16th to endNight
18%5%8%7%36%7%6%8%35%
2880

Percentage Cloud Cover SW (2006-)
Color Meanings:
Overcast 90% covered 80% covered 70% covered 60% covered 50% covered 40% covered 30% covered 20% covered 10% covered Clear
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
27%48%5%35%6%6%10%38%
1253
16th to endDay
27%5%9%8%35%45%8%37%
1515
February1st to 15thDay
27%47%7%46%5%7%8%35%
1435
16th to endDay
19%5%11%6%5%6%6%6%7%31%
1512
March1st to 15thDay
16%5%8%8%47%5%6%9%34%
1830
16th to endDay
6%11%7%10%8%46%6%5%9%23%
2150
April1st to 15thDay
11%15%6%7%5%345%6%8%25%
2227
16th to endDay
12%14%37%5%45%5%5%7%28%
2340
May1st to 15thDay
11%10%38%5%36%5%6%7%31%
2528
16th to endDay
22%8%37%5%46%5%6%7%22%
2802
June1st to 15thDay
21%8%37%6%45%6%6%7%23%
2700
16th to endDay
14%5%25%6%45%6%7%9%31%
2700
July1st to 15thDay
10%5%245%36%6%6%8%39%
2700
16th to endDay
6%424335%6%7%8%45%
2779
August1st to 15thDay
12%424445%6%7%8%38%
2491
16th to endDay
9%3244245%5%8%48%
2483
September1st to 15thDay
12%5%14423345%50%
2098
16th to endDay
10%5%245%2445%8%46%
1815
October1st to 15thDay
11%9%38%6%345%5%9%32%
1681
16th to endDay
5%9%36%5%35%6%7%8%38%
1584
November1st to 15thDay
49%45%6%36%5%6%7%38%
1467
16th to endDay
310%6%6%5%2446%8%41%
1260
December1st to 15thDay
27%5%9%9%47%6%7%9%30%
1260
16th to endDay
29%37%6%26%5%8%11%35%
1344
January1st to 15thNight
29%48%7%36%6%6%8%33%
2685
16th to endNight
37%48%5%35%5%6%9%39%
2720
February1st to 15thNight
37%47%5%35%5%7%9%38%
2418
16th to endNight
28%6%10%7%35%45%6%38%
1962
March1st to 15thNight
27%47%7%46%7%7%10%34%
2129
16th to endNight
410%6%8%6%45%6%6%8%31%
2073
April1st to 15thNight
8%14%5%7%5%25%5%5%8%30%
1720
16th to endNight
9%13%36%5%2445%8%34%
1620
May1st to 15thNight
9%10%36%425%5%5%8%38%
1420
16th to endNight
20%8%36%6%2345%8%30%
1309
June1st to 15thNight
17%7%36%5%345%5%6%32%
1260
16th to endNight
12%3245%245%8%10%40%
1260
July1st to 15thNight
7%4145%35%6%7%7%47%
1260
16th to endNight
5%324325%5%5%8%53%
1388
August1st to 15thNight
11%3144225%6%10%47%
1467
16th to endNight
8%31222345%9%56%
1719
September1st to 15thNight
12%5%13323246%53%
1780
16th to endNight
10%41232345%8%50%
1815
October1st to 15thNight
11%8%35%6%35%45%6%38%
1945
16th to endNight
6%8%25%4346%5%8%43%
2288
November1st to 15thNight
39%35%5%25%46%8%44%
2380
16th to endNight
39%5%8%6%35%5%6%8%37%
2697
December1st to 15thNight
28%5%9%7%47%6%7%8%31%
2700
16th to endNight
19%48%8%36%6%6%9%33%
2880

Transparency (when cloud cover <= 30%)
Color Meanings:
Too cloudy to forecast Poor Below Average Average Above average Transparent
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
37%10%18%25%6%2
1253
16th to endDay
43%7%14%19%11%3
1515
February1st to 15thDay
40%11%15%21%8%2
1435
16th to endDay
47%9%15%16%9%
1512
March1st to 15thDay
41%12%18%20%6%
1830
16th to endDay
57%8%14%14%5%
2150
April1st to 15thDay
54%8%15%12%6%
2227
16th to endDay
53%8%14%16%6%1
2340
May1st to 15thDay
49%7%15%18%7%
2528
16th to endDay
59%8%14%12%4
2807
June1st to 15thDay
58%9%14%11%5%
2700
16th to endDay
47%10%17%17%6%1
2700
July1st to 15thDay
40%12%18%19%7%1
2541
16th to endDay
33%10%16%26%11%1
2605
August1st to 15thDay
40%11%19%20%6%1
2474
16th to endDay
32%8%18%29%10%1
2483
September1st to 15thDay
36%6%14%23%16%2
2098
16th to endDay
35%7%15%27%10%2
1815
October1st to 15thDay
46%9%14%17%10%
1681
16th to endDay
40%10%16%22%9%1
1584
November1st to 15thDay
39%10%16%21%10%1
1467
16th to endDay
38%8%18%22%8%2
1260
December1st to 15thDay
44%11%16%18%8%
1260
16th to endDay
38%9%15%21%11%2
1344
January1st to 15thNight
43%11%17%17%7%2
2685
16th to endNight
39%9%14%20%12%3
2720
February1st to 15thNight
38%10%15%21%11%1
2429
16th to endNight
44%6%13%19%14%1
1962
March1st to 15thNight
38%11%20%21%7%
2129
16th to endNight
45%10%14%19%8%
2073
April1st to 15thNight
49%7%15%18%8%
1720
16th to endNight
47%8%15%21%5%1
1620
May1st to 15thNight
42%7%16%23%9%
1421
16th to endNight
51%7%17%17%41
1309
June1st to 15thNight
49%8%14%18%8%
1260
16th to endNight
35%9%19%25%8%1
1260
July1st to 15thNight
32%9%17%29%10%
1190
16th to endNight
28%8%17%32%12%1
1299
August1st to 15thNight
30%8%19%30%9%
1459
16th to endNight
23%6%18%32%15%2
1719
September1st to 15thNight
31%416%25%18%2
1780
16th to endNight
30%6%18%27%13%3
1815
October1st to 15thNight
42%8%14%21%10%1
1945
16th to endNight
35%10%17%25%10%
2288
November1st to 15thNight
35%8%16%23%14%1
2380
16th to endNight
42%8%17%16%10%3
2697
December1st to 15thNight
44%12%14%20%7%1
2700
16th to endNight
41%11%14%21%10%1
2880

Seeing (when cloud cover <= 80%)
Color Meanings:
Too cloudy to forecast Bad 1/5 Poor 2/5 Average 3/5 Good 4/5 Excellent 5/5
MonthDays in MonthOccurrence of each ForecastData
Points
January1st to 15thDay
6%6%20%33%20%13%
60
16th to endDay
7%12%31%25%14%9%
64
February1st to 15thDay
5%17%41%26%42
67
16th to endDay
5%15%28%40%9%
171
March1st to 15thDay
6%24%50%17%1
270
16th to endDay
13%26%36%18%5%
288
April1st to 15thDay
21%22%31%19%4
269
16th to endDay
26%17%28%18%5%2
270
May1st to 15thDay
16%15%31%22%9%3
353
16th to endDay
25%10%19%25%16%3
517
June1st to 15thDay
23%10%28%22%12%2
495
16th to endDay
15%9%30%29%11%4
495
July1st to 15thDay
14%6%24%29%21%3
475
16th to endDay
9%9%33%30%12%3
448
August1st to 15thDay
16%5%29%32%12%4
315
16th to endDay
12%12%29%31%9%4
332
September1st to 15thDay
19%9%30%27%10%4
300
16th to endDay
16%19%31%23%8%1
255
October1st to 15thDay
20%12%34%23%9%
165
16th to endDay
9%431%31%18%5%
96
November1st to 15thDay
17%13%38%25%31
90
16th to endDay
8%13%25%26%11%15%
60
December1st to 15thDay
18%31%35%16%6%
60
16th to endDay
10%15%25%29%14%4
64
January1st to 15thNight
8%15%43%24%6%
900
16th to endNight
7%16%42%23%8%1
800
February1st to 15thNight
5%14%38%24%13%3
704
16th to endNight
6%7%38%28%15%2
632
March1st to 15thNight
5%11%46%25%8%2
720
16th to endNight
8%10%36%32%10%1
768
April1st to 15thNight
14%12%30%31%10%1
640
16th to endNight
16%10%28%30%13%
540
May1st to 15thNight
15%8%26%30%17%1
407
16th to endNight
24%421%27%20%1
375
June1st to 15thNight
21%6%21%32%16%1
360
16th to endNight
15%125%33%22%1
360
July1st to 15thNight
11%218%39%26%1
340
16th to endNight
6%320%42%25%1
376
August1st to 15thNight
14%111%33%33%5%
387
16th to endNight
11%319%39%23%2
573
September1st to 15thNight
15%320%28%23%8%
667
16th to endNight
12%5%30%30%14%5%
656
October1st to 15thNight
16%7%29%28%14%3
660
16th to endNight
10%9%33%33%10%2
704
November1st to 15thNight
9%15%45%22%5%1
805
16th to endNight
8%12%45%23%7%1
900
December1st to 15thNight
6%14%38%27%9%2
900
16th to endNight
6%13%40%27%9%2
960
Page generated at 2017-09-13 05:39:15. Version ac04

Copyright 2017 A. Danko


Bragg Creek Clear Sky Chart | Charts Home